The invention relates to a front plug system for a flat component, and more particularly to a front plug system including one front element and one front plug connector attachable to the front element with a swing motion.
Many electrical circuits are fabricated in a compact form, possibly including integrated circuits, on a flat component. In these electrical circuits, signal groups, such as data busses, are routed toward the edge of the flat component. Signals of this type can then be displayed at the front of the flat component for purposes of circuit diagnostics, indicating, monitoring and measuring. The signals may also be tapPed at the front of the flat component and, if necessary, may be redirected across additional connections. In contrast, signal groups, which constantly need to be exchanged between circuit parts disturbed over several flat components, are preferentially redirected across stationary flat ribbon cable connections on the back sides of sub-racks.
To tap and apply electrical signals on the front faces of components closely arranged in sub-racks parallel to each other, front systems are used consisting of front elements firmly connected with the particular component and a front plug connector which can be attached on the component. For example, in the European patent application having publication number 0 129 883 and application number 84 107 202.8 a front system is disclosed for components, which can be slid into sub-racks, and frame-like sub-racks to hold them. On the front strip of the particular flat component a socket for receiving a front plug is provided, with which given electrical signals can be diverted preferentially across a cable. However, such an arrangement has the disadvantage that a front plug sitting in the socket can not, or only with additional expense, be safeguarded against being unintentionally pulled off. Furthermore, in a plugging process, the contacts may make contact in an unpredictable or accidential sequence. Consequently, to avoid feedback effects on the circuit on the flat component it may become necessary before plugging takes place to briefly take this circuit completely out of operation. In the case of several components combined in a sub-rack, the entire arrangement may be taken out of operation by separating it from the power supply.
The German patent having publication number 28 50 093 further discloses a holding arrangement for circuit boards. One electrical connecting element associated with the particular circuit board is swingable from a waiting position into an operating position, in which it engages on the circuit board. This arrangement also has the disadvantage that the contacts disposed on the front face of the circuit board in the transition from the waiting position to the operating position are not closed simultaneously. In a piece of equipment, to which these tapped signals are supplied for further processing, at least transitory error functions can occur. Furthermore, in this arrangement the electrical connecting element is also not secured against being unintentionally swung into the waiting position.